Efficacy and safety assessment of different electrode placements during electroconvulsive therapy for the treatment of depression: a comparison of bitemporal, bifrontal and unilateral right-sided stimulation - a narrative review

Abstract

Introduction: Consequences of depressive syndrome are changes in central nervous system, especially the reduction in volume and disturbances in neuronal metabolism. There are disturbances in cerebral blood flow, in areas responsible for concentration, memory and regulation of behaviour and emotions. ECT method has shown considerable effectiveness in treatment of depression. It has invariably remained effective as a form of treatment in psychiatry for many years. The way in which the method itself is applied and location of stimulation electrodes remains controversial. In clinical practice, bitemporal, bilateral or right unilateral applications are used, each of which activates slightly different regions in brain, resulting in different therapeutic effects. Methods: A review of available literature was performed by searching PubMed and Google Scholar databases, using the following keywords: bifrontal ECT, bitemporal ECT, right unilateral ECT, cognitive function for original papers, meta-analyses and review papers in Polish and English published from 1990 to 2022. The SANRA scale was used to maintain the high quality of the narrative review. Results: All three methods are effective in treating depressive disorders, but differ in impact on cognitive function. Bi-frontal stimulation is the most effective in emergencies, however related to a higher risk of cognitive impairment. Milder cognitive impairment, with similar therapeutic efficacy, is observed with bitemporal and unilateral placement. Conclusions: Individualised selection of ECT method is recommended, depending on patients' needs and clinical condition. The importance of individualising the dose, location of electrodes, and monitoring of cognitive function is emphasised in order to increase the effectiveness and minimise side effects. Keywords: bifrontal ECT, bitemporal ECT, right unilateral ECT, cognitive function